Turbine engine cycle temperature control system

ABSTRACT

A turbine engine, provided with a fuel control, has a gasifier section and a free turbine power section with energizeable clutching means adapted for at least at times causing frictional engagement between the sections in order to vary the then existing temperature within a selected point of the engine to cause that temperature to change to a value consistent with prescribed limits for that temperature.

[ 51 May 9,1972

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WWWVM 1256832 05929 0 9 298806 2366547 2332333 n m M a E h. w T .w S Mv. v m S e D. L mm E0 W C L v C 1 m Y m a C a m EC 0 m N D 8 G m N m munE 6m A R HM R W e BP m m RM m .m UE V TT 1m.A M T N 5 7 rgizeable gfrictional ry the then expoint of the engine to ge to a value consistentwith ABSTRACT A turbine engine, provided with a fuel control, has a 13Claims, 8 Drawing Figures ting temperature within a selected cause thattemperature to chan Primary EmminerClarence R. Gordon Attorney-WalterPot'oroka. Sr.'

section and a free turbine power section with ene clutching meansadapted for at least at times causin engagement between the sectionsin'order to va prescribed limitsfor that temperature.

[22] Filed: Apr. 20, 1970 [21] Appl.No.: 29,864

[581 FieldofSearch [56] References Cited UNITED STATES PATENTS 3,433,3193/1969 PATENTEDMAY 9 L972 3. 660, 976

SHEET 3 OF 3 I NVENTOR Qqymozza' 1? Cana/e I 25 6 ATTORNEY TURBINEENGINE CYCLE TEMPERATURE CONTROL SYSTEM BACKGROUND OF THE INVENTION Gasturbine engines may be classified broadly into three groups such as l)turbojet, (2) turboprop and (3) turboshaft. The turbojet engine is onewhich relies upon jet thrust to develop its propulsive force, whereas, aturboprop has its engine shaft coupled to a propeller, so as to developits propulsive force by slightly increasing the velocity of a large massof air. The turboshaft engine differs from the turboprop in that theturbine shaft is coupled to an output shaft which might drive somethingother than a propeller. Such output shaft may, for example, be -a driveshaft for a land based vehicle such as a truck or a stationary powerplant.

Regardless of the type of engine, it has been discovered that bestefficiency for a gas turbine engine is attained when certain cycletemperatures are maintained within prescribed accurate limits.

Accordingly, the invention as herein disclosed and claimed is concernedwith the provision of means whereby such selected cycle temperatures maybe controlled during engine operation.

SUMMARY OF THE INVENTION According to the invention, a cycle temperaturecontrol system for a turbine engine having a gasifier section, comprisesfirst means for sensing a selected. cycle temperature within saidturbineengine and for producing a first signal of a variable magnitudein accordance with the magnitude of said cycle temperature, second meanseffective to at times operatively engage said gasifier section in orderto at least partially retard the rotation of said gasifier section, andthird control means for receiving said first signal, said third controlmeans being effective whenever the magnitude of said first signal inless than a first predetermined magnitude to cause actuation of saidsecond means in order to retard rotation of said gasifier section.

Various objects and advantages of the invention will become apparentwhen reference is made to the following detailed description consideredin conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS In the drawings, wherein certain details orelements may be omitted from one or more views for purposes of clarity:

FIG. 1, illustrates a turbine engine, provided with a fuel control, andembodying the temperature control system of the invention;

FIG. 2, is an enlarged axial cross-sectional view of one of the elementsdiagrammatically shown in FIG. 1;

FIGS. 3, 4, 5 and 6 are views respectively illustrating otherembodiments and modifications of the invention;

FIG. 7 is a partially diagrammatic view of a portion of the inventionshown in FIG. 6; and

FIG. 8 is a cross-sectional view taken generally on the plane of line8-8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in greater detailto the drawings, FIG. 1 illustrates a free turbine type of engine 10whose fuel supply is controlled as by a scheduling type of fuel control12. The engine 10 is illustrated, somewhat schematically, as beingcomprised of an outer housing 14, provided with a suitable air inlet 16,containing a gas producer or gasifier section 18 and a power outputor'free turbine section 19.

The gas producer section 18 is comprised of a compressor 20 operativelyconnected, as by a shaft 21, to a compressor turbine wheel 22 which, asis well known in the art, serves to drive the compressor 20. The freeturbine section 19 may be comprised of a power turbine wheel 23 suitablymounted as on a hollow shaft 24, joumalled within the engine 10, throughwhich a shaft extension 25, connected to the gasifier section 18, freelypasses.

As shown, the right end of hollow shaft 24 may have provided thereon agear 26 which is in meshed engagement with a first gear 27 and a secondoutput gear 29 having a shaft 31 connected thereto and functioning as aninput shaft to, for example, a power transmission assembly 33 which, inturn, may have a suitable output shaft 35.

Gear 27 is operatively connected to a shaft 37 which, at its other. end,is connected to a suitable clutching mechanism 39 generally comprised ofa rotatable outer housing 4l having one or more clutch plates 43 securedtherewithin and an inner disposed body 45 carrying one or more clutchplates 47 arranged so as to be engageable with clutch plates 43. Theouter portion of housing 41 carries a gear portion 49 meshed with a gear51 secured to the end of shaft extension 25. The clutch assembly 39 isillustrated only to the detail deemed necessary to convey the teachingsof the invention and the precise construction thereof is not importantsince, as will become apparent, the invention may be practiced byvarious braking or clutching mechanisms well known in the art. However,for purposes of discussion, it will be assumed that the clutchingmechanism 39 is one which is actuated hydraulically; that is, asincreased hydraulic pressure is directed to the interior of outerhousing 41 the clutch plates 43 and 47 are urged toward or against eachother with an increasing force so as to frictionally form at least adegree of drive connection therethrough.

The turbine engine 10, of course, could be employed as a land-basedstationary power plant, one employed in combination with either a landor water vehicle, as well as being employed as an aircraft power plant.

The fuel control 12, having a housing 36, is illustrated as comprisingva fuel inlet conduit 38 which communicates generally between a generalcavity or chamber 40, within housing 36, and a fuel supply conduit 42communicating with a fuel pump 44. Inlet conduit 38, is provided with arestriction 46 the purpose of which will become apparent as the description progresses. Alternatively, a so-called muscles" valve, which iswell knownin the art, may be employed in place of restriction 46.

Cavity or chamber 40communicates with a passageway 48 which, in turn,communicates with conduits 50 and 52. Conduit 50 communicates, as byconduit means 54, with speed sense means 56 operatively connected as bysuitable motion transmission means 58 to the shaft 21 as by means ofmeshed gears 62 and 64 of which 64 is connected to the shaft 21 andcompressor 24 for rotation therewith.

Conduit 52 is in controlled communication with a bypass conduit 66leading, as by suitable conduit means 68, to conduit means 70 upstreamof the fuel pump 44. A bypass valve 72 operatively connected to apressure responsive diaphragm assembly 74 is, as will become evident,normally urged downwardly toward a position closing communicationbetween conduits 52 and 66. Diaphragm assembly 74 may be suitablyretained between housing 36 and housing portion 76 so as to form twogenerally distinct but variably chambers 78 and 80. As will be noted,bypass valve 72 is provided with a plurality of radial passages 82 whichcontinually complete communication between the interior 84 of bypassvalve 72 and chamber 80.

A second diaphragm assembly 86 suitably secured between first housingportion 76 and a second housing portion 88, so as to form two generallydistinct but variable chambers 90 and 92, is operatively connected to amotion transmitting pushrod 94 which is slidably received through a wallof housing portion 76 so as to have its opposite ends generally receivedwithin chambers 92 and 78.

As can be seen, the diaphragm assembly 86 may include oppositelydisposed diaphragm backing plates 96 and 98 which may be secured to eachother, as to contain the diaphragm therebetween, by a suitable fastenerms passing therethrough. Similarly, diaphragm assembly 74 may beprovided with oppositely disposed diaphragm backing plates 102 and 104which also may be secured to each other, as to contain the diaphragmtherebetween, by a suitable fastener 106, which may be formed at one endof valve 72, passing therethrough. If desired, fastener 106 may beprovided with a bore for receiving therein one end of pushrod 94. Acompression spring 108, situated within chamber 80 normally resilientlyurges the diaphragm assembly 74 upwardly while a compression spring 110within chamber 90 resiliently urges the diaphragm assembly 86 downwardlythereby causing the pushrod 94 to be in abutting engagement at one endwith the diaphragm assembly 74 and valve 72 and, at the other end, withdiaphragm assembly 86. (As specifically illustrated, the motion or forcetransmitting pushrod 94 may actually abut against the fastner portions100 and 106 of diaphragm assemblies 86 and 74, respectively.)

Compressor discharge or burner inlet pressure, P sensed as by a probe112 is directed to chamber 90 as by conduit means 114 and 116 and arestriction 118 in series therewith. Chamber 90, containing compressionspring 110, normally urging diaphragm assembly 86 downwardly,communicates with the ambient atmosphere by means of a conduit 120 whichalso contains a restriction 122. Because of the flow afforded by thecombination of restrictions 118 and 122 the pressure, P within chamber90, although related to the value of P will be of a value somewhat lessthan the value of P For example, restrictions 118 and 122 may bedesigned so that as is the case in Applicants disclosed structure.Chamber 92 communicates with the ambient atmosphere as by means of aconduit 124 which communicates with conduit 120 downstream ofrestriction 122.

Chamber or cavity 40 has a cylindrical valve-guide portion 130 forslideably receiving therein a governor valve 132 suitably secured as atone end to a third pressure responsive diaphragm assembly 134 which maybe suitably secured between housing 36 and cover member 136 in a mannerforming a chamber 138 between the diaphragm assembly 134 and cover 136.A flanged sleeve-like variably positioned spring seat 140 is situatedgenerally about the cylindrical valve-guide 130 in a manner so as tocontain a compression spring 139 between seat 140 and diaphragm assembly134. A lever 142, generally hinged as at 144, has a bifurcated end 146which is adapted to straddle guide 130 in order to engage the uppersurface of spring seat 140. Intermediate to the ends thereof, lever 142is provided with a cam-follower portion 148 adapted to engage the camsurface of a cam member 150 mounted on a shaft 152 for rotationtherewith. As diagrammatically illustrated at 154, shaft 152 isoperatively connected to a power selector lever 156 so that, forexample, clockwise rotation of power lever 156 will cause correspondingrotation of shaft 152 and cam 150 thereby rotating lever 142 clockwiseabout pivot 144 is order to urge spring seat 140 downwardly therebyincreasing the loading of compression spring 139. Such loading of spring139, of course, urges diaphragm assembly 134 and governor valve 132,connected thereto, in the downward direction. A threadably adjustablestop 158 may be provided for limiting the degree of downward movement ofdiaphragm assembly 134 and governor valve 132.

Chamber 138, on the other side of diaphragm assembly 134, communicatesas by a conduit 168 with a conduit 170 which communicates generallybetween speed sense 56 and fuel supply conduit 42. As will be noted,conduit 170 contains a restriction 172 and conduit 168 communicates withconduit 170 at a point downstream of restriction 172.

, The purpose of speed sense 56, in the embodiment disclosed, is toprovide a pressure signal indicative of the speed of the gas producersection 18 (compressor and compressor drive turbine 22). One embodimentof the invention was successfully tested and operated employing a speedsense functionally equivalent to the speed sense as shown, for example,at in US. Pat. No. 3,073,115 issued Jan. 15, 1963, to Warren H. Cowleset al. In such an arrangement, restriction 172 would be functionallyequivalent to the restriction shown at "242" of said US. Pat. No.3,073,115. Such arrangements and their operations are at this timegenerally well known in the art. It might also be pointed out at thistime that pump 44 is provided with either an externally or internallyformed pressure relief and check valve assembly as shown at 174 withsuitable associated conduitry 176 and 178 communicating with valve 174and respectively with conduits 70 and 42.

As shown in FIGS. 1 and 2, means may be provided for enabling theemployment of some other control parameter, such as burner inlettemperature, for further qualifying the metered fuel flow to the engine.As schematically illustrated at 182, to a valve assembly 184 which isserially connected between conduit 186, leading from conduit 164, andconduit 188 leading to conduit 190. Generally, the valve assembly 184functions in a manner whereby a reduction in flow through the valveassembly 184 is experienced as probe 180 senses an increase intemperature.

FIG. 2 illustrates in greater detail one embodiment of a probe 180 andvalve assembly 184 suitable for use in the arrangement of FIG. 1. Valveassembly 184 is illustrated as being comprised of a housing 192 havingan inlet conduit 194 and an outlet conduit 196 generally between whichis situated a valve orifice and seat 198. A valve member 200, carried asat the end of a stem portion 202, is situated so as to vary theeffective area of orifice 198 depending on the relative proximity of thevalve member 200. Stem 202, provided with a shoulderlike pile portion204 slideably received within a cylindrical guide-way 206 formed inhousing 192, has its opposite end operatively secured to one end of atemperature sensing rod 208. The other end of rod 208 is secured to anend cap member 210 which cooperates with a recessed portion of housing192 to axially contain therebetween a second temperature sensing member212 of cylindrical configuration. Cylinder 212 and rod 208 havedifferent coeficients of thermal expension resulting in a predictableaxial movement of valve member 200 per degree of temperature variation.The temperature probe 180 is also preferably provided with a protectiveshroud 214, which is perorated as at 216, in order to protect the rod208 and cylinder 212 from possible damage. The entire assembly may besecured to the housing 14 of engine 10 by any suitable means such as thefastener and seal respectively illustrated at 218 and 220.

OPERATION OF THE FUEL CONTROL Fuel at a pressure P, is supplied by pump44 through conduit 42 to conduit 38 and through muscles restriction 46situated within conduit 38. An accompanying drop in pressure acrossrestriction 46 results in the fuel within chamber 40 being at samepressure P, which is less than P,. Further, it can be seen that conduit168 supplied fuel from conduit to chamber 138 at a pressure P, which isusually less than pressure P However, it should be apparent that as thespeed sense 56 senses greater gasifier section speeds, the throttlingvalve contained therein becomes more nearly closed, resulting in thedifferential pressure P P increasing in magnitude. The ultimate maximumvalue of pressure P would, of course, be pressure P, upstream ofrestriction 172. A further pressure drop occurs with the passage of fuelthrough the aperture defined by orifice 162 and metering valve 160, sothat metered fuel downstream of orifice 162 is at a pressure P,. Asecond pressure drop occurs with the passage of fuel through theaperture defined by orifice 198 and valve 200 so that the metered fueldownstream of orifice 198 is at a pressure P An inspection of FIG. 1will disclose that a pressure difierential of P,P exists across thediaphragm assembly 74. (Pressure P, is communicated to chamber 78 bysuitable conduit means 222 in communication with conduit 190.) In otherwords, the force tending to open the bypass valve 72 is directly relatedto the pressure differention across the governor metering restrictionand temperature modifying valve 184.

Further, it can be seen that a pressure differential of P P, existsacross pressure responsive diaphragm assembly 134. Accordingly, aspressure differential P P increases and approaches the value of P, P,,as for example, by the increased rotational speed sense 56, a force iscreated across diaphragm assembly 134 tending to move governor valve 132upwardly toward a more nearly fully closed position.

When the engine is being made ready for cranking, the power selectorlever 156 is rotated to the desired power setting causing rotation ofshaft 152 which, in turn, rotates cam 150 clockwise. Such rotation ofcam 150 causes the contoured surface 224 to engage follower 148 andprogressively urge lever 142 clockwise about pivot 144 therebyincreasing the loading on spring 139 so as to urge diaphragm assembly134 and governor valve 132 downwardly to provide a maximum effectiveflow area through orifice 162. As the engine is being cranked, fuel pump44 provides a supply of fuel through conduit 42 to chamber 40 at apressure P which increases in magnitude as the pump speed increases, soas to flow through orifice 162, conduits 164, 186 and 190. A conduit226, formed in housing 36 effectively places conduit 190 incommunication, as through suitable conduit means 228, with the burner229. At this early stage of engine cranking or starting, the fuelpressure P will be sufficient to cause diaphragm assembly 74 to moveupwardly against the force transmitted by pushrod 94 thereby modulatingthe pressure differential of P P Once ignition is achieved, the enginecompressor 20, compressor turbine 22 and power turbine 23 begin toaccelerate to achieve the speed and/or power requested by the positionof the power selector lever 156. As' a consequence of the increase inspeed, fuel flow from pump 44 is increased with attendant increases inpressures P P and P within supply conduit 42 and chambers 40 and 138respectively.

Accordingly, it can be seen that the pressure differential of P P isincreasing across diaphragm assembly 134 tending to overcome the forceof spring 139 so as to urge governor valve 132 upwardly while, at thesame time, the pressure differential P P,,, which is also increasing, isbeing applied across diaphragm assembly 74 tending to move bypass valve72 upward in the opening direction.

Generally, compressor discharge pressure, P varies as the square of thespeed of the compressor 20; the speed signal, P P varies as the squareof the speed being sensed; and the weight-rate of fuel flow, W,, throughorifice 162 varies as the square root of the pressure differential P P,.It should also be pointed out that the flow-through the systemestablished by restrictions 118 and 122 permits the changing of pressureP, from one having a characteristic of varying as the square of thespeed of the compressor to a lesser relationship, as, for example,approximating the square (P of the compressor discharge pressure, Ppermitting the ultimate relationship of fuel flow, W,, to vary linearlywith respect to compressor discharge pressure, P,,,. This can beexpressed by the equations:

W,= K,A P, e P, 2" s s( rs) W 'E K, K 11 P Where:

K 1 a constant K a constant A cross-sectional flow area determined by162/160 and As engine speed (compressor speed) increases, pressurewithin respective chambers 90, 80, 40 and 138 also increases inaccordance with the cross-sectional area of orifice 162, the pressuredifferention P, P, and therefore the pressure differential P, P tends toincrease, causing a greater upward force to be applied to bypass valvediaphragm assembly 74. Accordingly, when the differential P P, (APincreases to a predetermined value (for the conditions established) theresulting upward force on diaphragm assembly 74 equals, and then to aslight degree exceeds, the force transmitted by. pushrod 94 so as toopen bypass valve 72 in order to bypass fuel from chamber 40 and conduit48 through conduit 52 to the inlet side of the fuel pump 44 as byconduit means 66, 68 and 70. Bypass valve 72 will be moved toward andaway from the closed position in order to maintain the particularpressure differential AP,, so as to keep the engine operating at thegoverned steady state condition.

If it is now assumed that it is desired to increase the output of theengine from some first point of steady state operation to a second pointof steady state operation, the only thing that needs to be done is torotate the power selector lever 156 further to the right in order tocause an additional incremental clockwise rotation of shaft l52and camso as to have the cam surface 224 further depress end 146 of lever 142.This, in turn, causes a greater loading on spring 139 and diaphragmassembly 134 to the point that the force created by pressure differential P P (AP,,) is over come, thereby moving governor valve 132downwardly and increasing the effective flow area of orifice 162.

As a consequence, increased fuel achieved resulting in increases in thepressor discharge pressure, P pressure, P and speed sense differentialpressure P P The increase in P causes diaphragm assembly 86 to exert afurther force on pushrod 94 against diaphragm assembly 74 so as to tendto close the bypass valve 72 and maintain P P (AP,) in proportion to PAccordingly, as before, when pressure differential P, P, increasessufficiently, governor valve 132 is moved upwardly an amount sufficientto meter the desired weight rate of fuel flow and bypass valve 72 ismoved upwardly so as to maintain the desired AP across the meteringorifice 162.

For a controlled deceleration, the power selector lever 156 is rotatedto a lower counterclockwise position thereby permitting end 146 of lever142 to move to its upper-most position. This reduces the load on spring139 and permits P; P, to move governor valve 132 to its upper-mostposition so as to, for example, engage the minimum fuel flow abutment orstop 166.

In view of the preceeding, it should also be apparent that speed sense56 provides an overrun protection. That is, if for some reason the load,as experienced by shaft 31, was suddenly removed, the engine would tendto overspeed and depending on the magnitude of the lost load, suchoverspeed could be critical. Accordingly, it can be seen that any suchtendency to overspeed is sensed by speed sense 56, which, inturn,creates a related increase in the differential pressure P, P, so as tomove the governor valve upwardly thereby reducing the fuel flow so as toprevent an otherwise uncontrolled overspeed. Further, it should beapparent that the temperature probe and associated valving assembly 184function to define an area wherein a family of generally linearfuelflow-to-compressordischarge-pressure schedule will exist dependingupon the then particular temperature sensed by the probe 180.

The acceleration system, comprised generally of bypass valve 72,diaphragm assemblies 74, 8 6, pushrod 94 and restrictions 118, 122provides an arrangement where only very slight movements are necessaryin order to control the opening and closing of the bypass valve 72. Itcan be seen that the force created by P acting on diaphragm assembly 86is transmitted to the bypass valve 72 by the solid pushrod or forcetransmitting member-94. Since bypass valve motion is very slight, totalmotion of diaphragm assembly d6 is relatively insignificant andtherefore friction effects on the pushrod 94, as by the seal 93, arenegligible.

flow to the engine is compressor sped, com- It will be noted, in FIG. 1,that chamber 90, within housing portion 88, has a first branch conduit230, in communication therewith, with a resiliently biased valve member232 seated against and closing the other end of conduit 230. Spring 234may be adjustably preloaded by the adjustable spring seat 236. As can beseen, when a predetermined value of P is attained (or exceeded) valve232 is moved off its cooperating seat thereby venting such excesspressure through conduit 230 and conduit 238 to conduit 120 at a pointdownstream of restriction 122. Therefore, it can be seen that a maximumvalue of P P and therefore fuel flow, for a given temperature as sensedby probe 180, is limited or determined by the relief valve 232 preloadedto open at a desired value of P As was previously stated, it has beendetermined that the efficiency of a turbine engine is greatly increasedif the T temperature of the engine can be maintained within prescribedlimits (such limits being determined by the characteristics of theparticular engine being considered).

In the embodiment of FIG. 1, the T temperature is sensed as by asuitable probe 240 situated generally between the burner section 229 andthe compressor turbine wheel 22. Even though not specifically shown itshould, nevertheless, be made clear that the probe 240 could be locatedbetween the compressor turbine 22 and free turbine 23 or downstream ofthe free turbine 23. The choice of such locations would again,primarily, be dictated by the particular characteristics of the turbineengine.

In any event, the probe 240 would be connected as by suitable means 242,through which the T signal would be transmitted, to a control assembly244 which, in turn, may be operatively connected, as by means 245, tosuitable valving means 246 to which is supplied a suitable hydraulicfluid via conduit means 248 and pressurized by pump means 250. The pumpmeans 250 is supplied by a reservoir 252 which has a return conduit 254leading thereto from valve means 246. Additional conduit means 256interconnects valve means 246 and the clutching mechanism 39 so to, inaccordance with the dictates of control 244, direct either relativelyhigh or low hydraulic pressure to the interior of clutching assembly 39.

OPERATION OF CLUTCH CONTROL ARRANGEMENT OF FIG. 1

The control 244 may, of course, be comprised of various componentswhether electrical, electro-mechanical, mechanical or hydraulic. Suchwill become apparent when reference is subsequently made to specificembodiments of such a control disclosed herein. However, the control orcomputer device 244, nevertheless, serves the function of receivingappropriate signals from selected operating parameters, in thisinstance. T as measured between the burner 229 and gasifier turbine 22,and determining whether such signals are within the range of establishedlimits and, if not, initiating corrective action.

For example, let it be assumed that temperature T as sensed by probe 240is at a value less than the desired minimum value. The computer orcontrol 244 responds thereto by creating an appropriate output signal orsignal transmitting means 245 causing valving means 246 to be actuatedso as to direct relatively high pressure hydraulic fluid to clutchassembly 39, via conduit means 256, causing the clutch plates 43 and 47to frictionally engage each other. Such clutching, in turn, results in aretarding force being applied to the gasifier section 18 via gear 51 andshaft extension 25. The retarding of the otherwise free rotation of thegasifier section 18 results in a reduction in the speed signal, P; Pallowing valve 132 to move in a direction increasing fuel flow, whichresults in an increase in T When the temperature T finally achieves itsprescribed desired limit, control 244 removes the previously appliedsignal to valve means 246 permitting the hydraulic pressure withinclutching assembly 39 to be reduced to a value appropriate for thedesired T, temperature.

8 EMBODIMENT OF no. 3

FIG. 3 illustrates one specific embodiment of structure for practicingthe invention as disclosed by FIG. 1. In FIG. 3 the structure generallyidentified at 260 can be considered as comprising at least a portion ofcontrol 244 and including the valving means 246 of FIG. 1. Further, asuitable configuration of temperature probe assembly 240 is illustratedas comprising not only a temperature sensing portion 262 but also avalving portion or assembly 264 responsive thereto.

Referring in greater detail to the arrangement of FIG. 3, the valvingassembly 264 is illustrated as being comprised of a housing 266 havingan inlet conduit 268 and an outlet conduit 270 generally between whichis situated a valve orifice and seat 272. A valve member 274, carried asat the end of a stem portion 276, is situated so as to vary theeffective area of orifice 272 depending on the relative proximity of thevalve member 274. Stem 276, provided with a shoulding like portion 278slidably received within a cylindrical guide-way 280 fonned in housing266, has its opposite end operatively secured to one end of atemperature sensing rod 282 forming a portion of the temperature sensingsection 262.

The temperature sensing section 262 is illustrated as comprising the rod282 having its other end secured to an end cap member 284 whichcooperates with a recessed portion of housing 266 to axially containtherebetween a second temperature sensing element member 286 ofcylindrical configuration. Cylinder 286 and rod 276 have differentcoeffecients of thermal expansion resulting in a predictable axialmovement of valve member 274 per degree of temperature variation. Thetemperature probe 240 is also preferably provided with a protectiveshroud 288, which is perforated as at 290, in order to protect the rod282 and cylinder 286 from possible damage. The entire assembly may besecured to the housing 14 of engine 10 by any suitable means such as thefastener and seal respectively illustrated at 292 and 294.

The structure 260 is illustrated as being comprised, generally, ofhousing sections 296 and 298 operatively secured to each other in amanner so as to contain therebetween a diaphragm 300, peripherally, inorder to define at opposite sides thereof distinct but variable chambers302 and 304. Suitable diaphragm backing members 306 and 308 effectivelycontain the diaphragm 300 therebetween and operatively connect it to astem portion 310 of valving means 246.

Chamber 302 contains an evacuated spring-like bellows assembly 312 whichhas its opposite ends respectively fixedly secured to end wall 314 andto the diaphragm 300 or associated diaphragm backing plates 306 and 300.Chamber 302, by means of a conduit portion 316, communicates with asource fo compressor discharge pressure, P 112 as through conduit means114 which, as shown, also communicates with the inlet conduit 268 ofprobe assembly housing 266. Chamber 304, in contrast, communicates viaconduit means 320 with the outlet conduit 270 of housing 266. Suitableadjustment means 321 comprised of a branch conduit 322 communicatingwith conduit means 320 and a variably adjustable needle-like valve 324may be provided for bleeding a desired amount of pressure within conduitmeans 320 to the atmosphere.

The valving means 246 is illustrated as being comprised of ahydraulically balanced spool-type valve having valving lands 326 and 328joined by a portion 330 reduced cross-section and operatively connectedto the stem 310. oppositely disposed chambers 332 and 334 are vented viaconduit portions 336 and 338 to sump as by conduit means 254 whileconduit portion 340 is connected, via conduit means 248, to a source ofhydraulic fluid under pressure such as pump 250. The outlet of thevalving assembly 246 may be considered as forming a part of the conduitmeans 256 leading to the clutching means 39.

9 OPERATION OF THE EMBODIMENT OF FIG. 3

As previously stated, probe 240 senses T temperature and, generally,causes the valve 274 to move away from its cooperating seat and aperture272 as temperature T increases.

For purposes of illustration let it be assumed that temperature T, iswithin the prescribed or desired limits. At this time compressordischarge pressure, P will continue to be directed, via conduit means114 and 316 to chamber 302, exerting a downward pressure on diaphragm300, and valve 274 will have moved some distance upward permitting arelatively unrestricted flow of compressor discharge pressure throughorifice 272 and outlet 270. Since it is quite possible that some drop inpressure might occur, and for ease of reference the value of thepressure downstream of orifice 272 will be designated P Pressure Pthusly is directed to chamber 304 where it is applied to the undersideof diaphragm 300. (It should be evident that where a bleed arrangement,as illustrated by passage 322 and needle valve 324, is employed, thevalue of P will also be dependent upon the degree of bleed permittedthereby.)

At this time the upward force determined by the spring rate of bellows312 and the force of Pm applied against the lower side of diaphragm 300are in balance with the downward force against diaphragm 300 determinedby the pressure P within chamber 302. Accordingly, since the structure260 is in balance, the appropriate hydraulic pressure is directed viaconduit means 256 to the clutching mechanism 39.

However, if the temperature T should for some reason decrease to a valueless than the preseribed limits, valve 274 will be moved toward oragainst its cooperating orifice and seat 272 causing a reduction ineffective flow area of said orifice 272. This, in turn, causes a greaterpressure drop thereacross resulting in a decrease in the value of PSince the structure 260 was previously in balance, the reduction in thevalue of P now causes the diaphragm or pressure responsive means 300 tomove downwardly resulting in valve land 328 further openingcommunication between high pressure hydraulic inlet 340 and conduitmeans 256 leading to the clutching means 39. As previously explained,this has a retarding effect on the compressor turbine 22 which resultsin an increase in temperature T,. This retarding effect continues untilT is again within desired limits at which time the system returns to abalanced condition as shown.

The provision of the evacuated bellows 312, as will become apparent tothose skilled in the art in view of the teachings herein, providesautomatic altitude compensation for those situations wherein theapparatus may be used in varying altitudes.

EMBODIMENT OF FIG. 4

FIG. 4, in which elements like or similar to those of FIG. 3 areidentified with like reference numbers, discloses structure which may beconsidered as a modification of the arrangement of FIG. 3.

The embodiment of FIG. 4 would function in the same manner as that ofFIG. 3 with the exception that additional variable but distinct chambers340 and 342 are defined on opposite sides of a pressure developingmember or diaphragm 344 peripherally retained as between housingportions 296 and 346. Diaphragm backing members 348 and 350 operativelyconnect diaphragm 344 to an actuating rod or stem 352 which may have itsend 354 disposed for engagement by suitable actuating means 356 (whichmay take the form of a cam member) operatively connected and responsiveto the movement of the power selector lever 156 in the power increasingdirection. Chamber 340 may be vented to the atmosphere as by conduit 358while chamber 342 is placed in communication with chamber 304 by virtueof conduit means 360.

The purpose of the diaphragm 344 and associated actuating mechanism canbest be understood if it is first assumed that T,

is within the prescribed limits by virtue of some communication betweenhigh pressure in inlet 340 and in conduit means 256 past valve land 328.

If during this condition of operation an increase in power is desired,it is best to remove all retarding effect from the gasifier section 18in order to thereby enable the compressor 20 and compressor turbine 22to accelerate as quickly as possible. Accordingly, when the powerselector lever 156 is rotated in the power-increasing direction, theactuating means 336 causes a downward movement of stem 352 and diaphragm344. This displacement of diaphragm 344, along with the restrictionmeans 362, causes a sudden increase in the pressure of P within chamber342, conduit 360 and chamber 304 resulting in diaphragm 300 being atleast temporarily moved upwardly, moving valve land 328 with it, therebyventing the conduit means 256 and interior of clutching mechanism 39 tolow or sump pressure.

EMBODIMENT OF FIG. 5

All elements in FIG. 5 which are like or similar to those of eitherFIGS. 3 or 4 are identified with like reference numbers. Basically, thedifferences reside in the elimination of the altitude compensatingbellows means 312 of FIGS. 3 and 4, and the use of a biasing spring 364situated on a spring perch 366 through which an aperture 368, equivalentto conduit 360, is formed. Another basic difference is the use of amovable wall, in the form of a diaphragm 370 peripherally securedbetween housing sections 296 and 296a while being suitably connected atits niidportion to stem 310 as by opposed backing plates 372 and 374,one of which could well be a flange formed on the stem 310.

EMBODIMENT OF FIGS. 6, 7 and 8 FIG. 6 illustrates another embodiment ofthe invention wherein elements like or similar to those of the precedingFigures are identified with like reference numbers. In the arrangementshown, probe 240a may be a thermocouple for supplying a variable signalT via signal transmission means 242 to the computer or control 2440which may be comprised of suitable logic and control elements as, forexample, electrical circuitry as is well known in the art.

The computer 244a may also receive other input signals such as a speedsignal, N,, produced by the speed sensitive means 62, 62 in accordancewith the speed of gasifier 18, and applied to computer 244a via signaltransmitting means 400. A second temperature signal, T which is a lowreference temperature against which T is compared, may be produced as bysuitable potentiometer means 402 and directed to computer 244a viasignal transmitting means 404. As shown the signal N may be alsotransmitted as via means 406 so as to be applied to the potentiometermeans 402 in order to at times modify the value of the T signal producedthereby. That is, in certain situations it has been determined that afirst predetermined minimum temperature of T is desired for gasifierspeeds of, for example, up to and including 60 percent of its ratedmaximum speed, while an increasing minimum temperature related to theincrease in gasifier speed. Accordingly, this may be accomplished byproviding the potentiometer means 402 to be acted upon by the signal, Nwhen the signal N exceeds a value indicative of said 60 percent gasifierspeed, so as to thereby continually adjust the potentiometer means 402in order to progressively increase the value of the reference signal TAs was previously described, it is desireable to prevent the applicationof a retarding force on the gasifier section 18,

through the clutching means 39, whenever the engine 10 exever thetransmission assembly 33 experiences a shift point. This isdiagrammatically illustrated by a lever 410 operatively connected tosuitable signal generating means 412 adapted for applying a generatedsignal, SP, to computer 244A, via signal transmitting means 414,whenever the transmission 33 experiences a shift point.

FIG. 7 further illustrates, diagrammatically the computer or controlsection 244a of FIG. 6 as being comprised of an electrical differentialamplifier 416 which receives signals T and T along means 242 and 404,respectively. An output signal V is in turn created and applied as to aconductor 418 which may, in turn, have suitable current limiter means420 as well as suitable switching means 422, 424 and 426 in seriestherewith.

In this arrangement switch means 422 could be normally open andcontrolled by signal transmitting means 400 so as to thereby becomeclosed at some predetermined gasifier speed as, for example, possibly 60percent of its rated speed and remain closed for all gasifier speeds inexcess thereof. Switch means 424 could be normally closed andoperatively controlled by the signal transmitting means 408 so as tobecome opened whenever the signal, PL, appeared thereon. Similarly,switch means 426 could be normally closed and operatively controlled bythe signal transmitting means 414 so as to become opened whenever thesignal, SP, appeared thereon.

A torque motor assembly 430 comprised as of a field winding 432, whichmay be comprised of oppositely wound field coil each having an endconnected to ground via conductor 428 and having their respective otherends connected to conductor 418 by means of parallel conductors 418a and148b, situated within a suitable housing 434 which also contains anarmature member 436 suitably anchored as by a torsion type spring 438.The end of the armature 436 has a valve member 440 secured thereto as bya pivot pin 442. A passageway 444 formed in the housing 434 communicateswith a source of relatively high hydraulic pressure, as via conduitmeans 248, and has an open end 446 generally juxtaposed to valve 440. Asecond passageway 448 formed in housing 434 communicates with sumppressure, as by conduit means 254, and has an open end 450 generallyjuxtaposed to the opposite side of valve 440. A second passageway 448formed in housing 434 communicates with sump pressure, as by conduitmeans 254, and has an open end 450 generally juxtaposed to the oppositeside of valve 440. A third passageway 452 formed in housing 434communicates with the clutching means 39 as by conduit means 256.

During normal operation the torsion spring 438 in a generally nullposition as illustrated. However, should the signal '1, exceed thereference signal T the output signal V, will have a value causing thefield 432 to be energized in a direction causing armature 436 to rotatecounter-clockwise, about the axis of torsion spring 438, resulting invalve 440 more closely approaching (possibly closing off) the open end446 of high pressure supply conduit 444. Consequently, this causes thesump pressure of conduit 448 to be more fully communicated to theclutching assembly 39 by means of conduit means 452 and 256.

Similarly, if reference signal T should exceed the value of signal T theoutput signal V will have a value causing the field 432 to be energizedin a direction causing armature 436 to rotate clockwise, about the axisof torsion spring 438, resulting in valve 440 more closely approaching(possibly closing off) the open end 450 of sump pressure conduit 448.Consequently, this causes the high pressure of conduit 444 to be morefully communicated to the clutching assembly 39 as by conduit means 452and 256. Accordingly, it can be seen that the invention as hereindisclosed provides various arrangements defining a closed looptemperature control system applicable to various forms of turbineengines as well as providing for the accommodation of various overridingor corrective signals.

it should also be noted that a signal indicative of the speed of shaft24 or shaft 31 is compared to a desired maximum value, and, when thedesired maximum value is exceeded, control 244 (FIG. 1) or control 244a(FIG. 6) commands high pressure to clutch 39, hereby producing anon-slipping connection of free turbine section 19 to gasifier section18. This causes the gasifier section to tend to overspeed, which causesthe governor valve 132 to move in a direction decreasing fuel flow. Theresult is insufficient power to drive compressor 20, which thenconstitutes a load on the free turbine section 19, retarding itsrotational speed and preventing overspeed thereof. Such an arrangementcould be comprised of suitable speed responsive means 460 operativelyconnected to shaft 31 as by means 462 so as to produce a signal ontransmission means 464 leading to the control valve 246 whereby, uponthe occurrence of such an overspeed signal, control valve 246 can bemade to supply full high pressure to the clutch assembly 39.

Although only selected embodiments of the invention have been disclosedand described, it should be apparent that other embodiments andmodifications of the invention are possible within the scope of theappended claims.

I claim:

1. A cycle temperature control system for a turbine engine having agasifier section comprised of a compressor and a compressor turbinedriving said compressor and a free power turbine operatively connectedto power output transmitting means, comprising first means for sensing aselected cycle temperature within said turbine engine for producing afirst signal of a variable magnitude in accordance with the magnitude ofsaid cycle temperature, second means effective to at times at leastpartially retard the speed of said compressor and compressor turbine,and third control means for receiving said first signal, said thirdcontrol means being effective whenever the magnitude of said firstsignal is less than a first predetermined magnitude to cause actuationof said second means in order to retard the speed of said compressor andcompressor turbine, said second means comprising motion transmittingmeans operatively interconnecting said power turbine and said compressorwhereby upon actuation of said second means said second means iseffective to retard the speed of said compressor by transmitting atleast some of the rotational energy of said compressor through saidpower output transmitting means operatively connected to said free powerturbine.

2. A cycle temperature control system according to claim 1, includingfourth means effective for producing a second signal whenever said poweroutput transmission means is caused to experience a shift point, saidthird control means being effective to receive said second signal and inresponse thereto being rendered ineffective for causing said actuationof said second means, and including fifth means effective for producinga third signal whenever an increase of power is requested of saidengine, said third control means being effective to receive said thirdsignal and in response thereto being rendered ineffective for causingsaid actuation of said second means.

3. A cycle temperature control system according to claim 1, includingfourth means effective for producing a second signal whenever said poweroutput transmission means is caused to experience a shift point, saidthird control means being effective to receive said second signal and inresponse thereto being rendered ineffective for causing said actuationof said second means, fifth means effective for producing a third signalwhenever an increase of power is requested of said engine, said thirdcontrol means being effective to receive said third signal and inresponse thereto being rendered ineffective for causing said actuationof said second means, and sixth means responsive to rotational speed ofsaid gasifier section and effective for producing a fourth signalgenerally in accordance therewith, said third control means beingefi'ective to receive said fourth signal and in response thereto beingrendered ineffective for causing said actuation of said second meanswhenever said rotational speed of said gasifier section is less than apredetermined minimum rotational speed.

4. A cycle temperature control system according to claim 1, wherein saidmotion transmitting means comprises clutch means, wherein said thirdcontrol means comprises valving means operatively connected to moveablepressure responsive means exposed on one side to the discharge pressureof said compressor and exposed on an other side opposite to said oneside to a second pressure which is derived from said compressordischarge pressure, wherein said first means comprises a temperaturesensing probe operatively connected to associated second valving means,said probe being effective to control the position of said secondvalving means in accordance with said cycle temperature in order to varythe magnitude of said second pressure on said other side of saidpressure responsive means.

5. A cycle temperature control system according to claim 4, wherein saidmoveable pressure responsive means is operatively connected to thirdvalving means communicating generally between a source of relativelyhigh pressure actuatingfluid and said clutch means, said third valvingmeans being effective to complete communication between said source andsaid clutch means whenever the magnitude of said secondpressure on saidother side of said pressure responsive means has been sufficientlyreduced by said probe and as sociated second valving means.

6. A cycle temperature control system according to claim 4, includingcompensating means operatively connected to said pressure responsivemeans for automatically providing a compensating force thereagainst for,variations occurring in barometric pressure, said compensating meanscomprising resilient barometrically defiectable means continuallyresiliently urging said pressure responsive means in the direction ofsaid second pressure.

7. A cycle temperature control system according to claim 4, includingmoveable volumetric displacement means forming a wall of a chamber,wherein said other side of said pressure responsive means and saidchamber are exposed to said second pressure, said volumetricdisplacement means being adapted to be moved whenever increased power isrequested of said engine, said displacement means being effective uponbeing so moved to temporarily cause an increase in the magnitude of saidsecond pressure on said other side of said pressure responsive means,thereby moving said pressure responsive means in the direction of andagainst said compressor discharge pressure.

8. A cycle temperature control system according to claim 7, includingspring means operatively connected to said pressure responsive means,said spring means normally urging said pressure responsive means in adirection opposite to said other side of said pressure responsive means.

9. A cycle temperature control system according to claim 1, wherein saidsecond means also comprises clutch means, wherein said third controlmeans comprises electrical computer means, wherein said first meanscomprises a temperature sensing probe responsive to the temperature ofthe gas within said gasifier section immediately upstream of saidcompressor turbine, said probe being effective for producing anddirecting said first signal to said computer means, includingtemperature reference means effective for producing a second signal of amagnitude reflective of a predetermined reference temperature and fordirecting said second signal to said computer means, said computer meanscomprising comparator amplifier means for comparing the magnitudes ofsaid first and second signals and creating an output signal indicativeof the difference therebetween, and wherein said second means is adaptedto be responsive to said output signal and in accordance therewith beactuated or de-actuated in order to retard or release said compressorand compressor turbine.

10. A cycle temperature control system according to claim 9, includingmagnetically controlled valving means interposed generally between saidsecond means and source of relatively high pressure actuating fluid,said magnetically controlled valving means being adapted to receive saidoutput signal and be openable and closeable in response thereto in orderto thereby be effective for causing selective clutching and declutchingof said clutching means.

1. A cycle temperature control system according to claim 9, includingmeans operatively connected to said temperature reference means andresponsive to rotational speed of said compressor and compressorturbine, sand means responsive to the rotational speed of saidcompressor and compressor turbine being effective to variably adjustsaid temperature reference means in order to increase the magnitude ofsaid predetermined reference temperature as the rotational speed of saidcompressor and compressor turbine increases.

12. A cycle temperature control system for a turbine engine, comprisingfirst means for sensing a selected cycle temperature within said turbineengine and for producing a first signal of a variable magnitude inaccordance with the magnitude of said cycle temperature, second meanseffective to at times at least partially retard the speed of saidengine, and third control means for receiving said first signal, saidthird control means being efiective whenever the magnitude of said firstsignal is less than a first predetermined magnitude to cause actuationof said second means in order to retard the speed of said engine, poweroutput transmission means operatively connected to said turbine engine,and fourth means effective for producing a second signal whenever saidtransmission means is caused to experience a shift point, said thirdcontrol means being effective to receive said second signal and inresponse thereto being rendered ineffective for causing said actuationof said second means.

13. A cycle temperature control system for a turbine engine having agasifier section comprised of a compressor and a compressor turbine anda power turbine freely rotatable with respect to said compressor andcompressor turbine, comprising first means for sensing a selected cycletemperature within said turbine engine and for producing a first signalof a variable magnitude in accordance with the magnitude of said cycletemperature, second means effective to at times operatively engage saidcompressor and compressor turbine in order to at least partially retardthe rotation of said compressor and compressor turbine, third controlmeans for receiving said first signal, said third control means beingeffective whenever the magnitude of said first signal is less than afirst predetermined magnitude to cause actuation of said second means inorder to retard rotation of said compressor and compressor turbine, andfourth means effective for producing a second signal whenever the speedof rotation of said power turbine exceeds a predetermined rotationalspeed, said third control means being effective to receive said secondsignal and in response thereto being effective to cause said powerturbine and said gasifier section to be completely locked for rotationwith each other.

1. A cycle temperature control system for a turbine engine having agasifier section comprised of a compressor and a compressor turbinedriving said compRessor and a free power turbine operatively connectedto power output transmitting means, comprising first means for sensing aselected cycle temperature within said turbine engine for producing afirst signal of a variable magnitude in accordance with the magnitude ofsaid cycle temperature, second means effective to at times at leastpartially retard the speed of said compressor and compressor turbine,and third control means for receiving said first signal, said thirdcontrol means being effective whenever the magnitude of said firstsignal is less than a first predetermined magnitude to cause actuationof said second means in order to retard the speed of said compressor andcompressor turbine, said second means comprising motion transmittingmeans operatively interconnecting said power turbine and said compressorwhereby upon actuation of said second means said second means iseffective to retard the speed of said compressor by transmitting atleast some of the rotational energy of said compressor through saidpower output transmitting means operatively connected to said free powerturbine.
 2. A cycle temperature control system according to claim 1,including fourth means effective for producing a second signal wheneversaid power output transmission means is caused to experience a shiftpoint, said third control means being effective to receive said secondsignal and in response thereto being rendered ineffective for causingsaid actuation of said second means, and including fifth means effectivefor producing a third signal whenever an increase of power is requestedof said engine, said third control means being effective to receive saidthird signal and in response thereto being rendered ineffective forcausing said actuation of said second means.
 3. A cycle temperaturecontrol system according to claim 1, including fourth means effectivefor producing a second signal whenever said power output transmissionmeans is caused to experience a shift point, said third control meansbeing effective to receive said second signal and in response theretobeing rendered ineffective for causing said actuation of said secondmeans, fifth means effective for producing a third signal whenever anincrease of power is requested of said engine, said third control meansbeing effective to receive said third signal and in response theretobeing rendered ineffective for causing said actuation of said secondmeans, and sixth means responsive to rotational speed of said gasifiersection and effective for producing a fourth signal generally inaccordance therewith, said third control means being effective toreceive said fourth signal and in response thereto being renderedineffective for causing said actuation of said second means wheneversaid rotational speed of said gasifier section is less than apredetermined minimum rotational speed.
 4. A cycle temperature controlsystem according to claim 1, wherein said motion transmitting meanscomprises clutch means, wherein said third control means comprisesvalving means operatively connected to moveable pressure responsivemeans exposed on one side to the discharge pressure of said compressorand exposed on an other side opposite to said one side to a secondpressure which is derived from said compressor discharge pressure,wherein said first means comprises a temperature sensing probeoperatively connected to associated second valving means, said probebeing effective to control the position of said second valving means inaccordance with said cycle temperature in order to vary the magnitude ofsaid second pressure on said other side of said pressure responsivemeans.
 5. A cycle temperature control system according to claim 4,wherein said moveable pressure responsive means is operatively connectedto third valving means communicating generally between a source ofrelatively high pressure actuatingfluid and said clutch means, saidthird valving means being effective to complete communication betweensaid source and said clutch meanS whenever the magnitude of saidsecondpressure on said other side of said pressure responsive means hasbeen sufficiently reduced by said probe and associated second valvingmeans.
 6. A cycle temperature control system according to claim 4,including compensating means operatively connected to said pressureresponsive means for automatically providing a compensating forcethereagainst for variations occurring in barometric pressure, saidcompensating means comprising resilient barometrically deflectable meanscontinually resiliently urging said pressure responsive means in thedirection of said second pressure.
 7. A cycle temperature control systemaccording to claim 4, including moveable volumetric displacement meansforming a wall of a chamber, wherein said other side of said pressureresponsive means and said chamber are exposed to said second pressure,said volumetric displacement means being adapted to be moved wheneverincreased power is requested of said engine, said displacement meansbeing effective upon being so moved to temporarily cause an increase inthe magnitude of said second pressure on said other side of saidpressure responsive means, thereby moving said pressure responsive meansin the direction of and against said compressor discharge pressure.
 8. Acycle temperature control system according to claim 7, including springmeans operatively connected to said pressure responsive means, saidspring means normally urging said pressure responsive means in adirection opposite to said other side of said pressure responsive means.9. A cycle temperature control system according to claim 1, wherein saidsecond means also comprises clutch means, wherein said third controlmeans comprises electrical computer means, wherein said first meanscomprises a temperature sensing probe responsive to the temperature ofthe gas within said gasifier section immediately upstream of saidcompressor turbine, said probe being effective for producing anddirecting said first signal to said computer means, includingtemperature reference means effective for producing a second signal of amagnitude reflective of a predetermined reference temperature and fordirecting said second signal to said computer means, said computer meanscomprising comparator amplifier means for comparing the magnitudes ofsaid first and second signals and creating an output signal indicativeof the difference therebetween, and wherein said second means is adaptedto be responsive to said output signal and in accordance therewith beactuated or de-actuated in order to retard or release said compressorand compressor turbine.
 10. A cycle temperature control system accordingto claim 9, including magnetically controlled valving means interposedgenerally between said second means and source of relatively highpressure actuating fluid, said magnetically controlled valving meansbeing adapted to receive said output signal and be openable andcloseable in response thereto in order to thereby be effective forcausing selective clutching and de-clutching of said clutching means.11. A cycle temperature control system according to claim 9, includingmeans operatively connected to said temperature reference means andresponsive to rotational speed of said compressor and compressorturbine, sand means responsive to the rotational speed of saidcompressor and compressor turbine being effective to variably adjustsaid temperature reference means in order to increase the magnitude ofsaid predetermined reference temperature as the rotational speed of saidcompressor and compressor turbine increases.
 12. A cycle temperaturecontrol system for a turbine engine, comprising first means for sensinga selected cycle temperature within said turbine engine and forproducing a first signal of a variable magnitude in accordance with themagnitude of said cycle temperature, second means effective to at timesat least partially retard the speed of said engine, and third controlmeans for receiving said first signAl, said third control means beingeffective whenever the magnitude of said first signal is less than afirst predetermined magnitude to cause actuation of said second means inorder to retard the speed of said engine, power output transmissionmeans operatively connected to said turbine engine, and fourth meanseffective for producing a second signal whenever said transmission meansis caused to experience a shift point, said third control means beingeffective to receive said second signal and in response thereto beingrendered ineffective for causing said actuation of said second means.13. A cycle temperature control system for a turbine engine having agasifier section comprised of a compressor and a compressor turbine anda power turbine freely rotatable with respect to said compressor andcompressor turbine, comprising first means for sensing a selected cycletemperature within said turbine engine and for producing a first signalof a variable magnitude in accordance with the magnitude of said cycletemperature, second means effective to at times operatively engage saidcompressor and compressor turbine in order to at least partially retardthe rotation of said compressor and compressor turbine, third controlmeans for receiving said first signal, said third control means beingeffective whenever the magnitude of said first signal is less than afirst predetermined magnitude to cause actuation of said second means inorder to retard rotation of said compressor and compressor turbine, andfourth means effective for producing a second signal whenever the speedof rotation of said power turbine exceeds a predetermined rotationalspeed, said third control means being effective to receive said secondsignal and in response thereto being effective to cause said powerturbine and said gasifier section to be completely locked for rotationwith each other.